Patent GB-289157-A (GB)
Title: Improvements in or relating to apparatus for casting printing plates
IPC: B41D3/00
Filed: 1927-01-21
Abstract: 289,157. Marks, E. C. R., (Wood Newspaper Machinery Corporation). Jan. 21, 1927. Stereotype, casting and finishing. - In a machine for casting and trimming stereotype printing-plates, a device is provided whereby the machine can be set to perform automatically all the operations necessary for the production of a predetermined number of plates and then to come to a stop. The machine comprises a vertical rotatable core, a reciprocable back, metalpouring devices, and plate-trimming mechanism. Core-operating mechanism. The core 38 is rotatably mounted on a vertical support 39, and is rotated from constantly moving shafts 22, 24, Figs. 1 and 2, driven by a motor 21 carried on the frame 20 of the machine. The rotation is controlled by a clutch 32 on a shaft 27 mounted on the core, the clutch being operated either manually or automatically by means of a lever 35. The lever is under the influence of a spring 40 which tends to hold a roller on the lever in one of two diametrically-opposed notches in a cam 30 secured to the core, the clutch being then open. The lever 35 provided on its underside with a tooth 44 adapted to be engaged by a spring-pressed pawl 45 on the reciprocating back 77 of the mould. The pawl 45 slides past the tooth when the back moves towards the core to complete the mould, but when the back is retracted, the tooth and pawl engage to move the lever and close the clutch, thus setting the core in rotation. Back-operating mechanism. The back is movable in the frame 20, and is connected by links 74 to cranks 64<a> on a shaft 64, the crank-pins being adjustable in the links by means of eccentric bearings. The shaft 64 is driven by a wormwheel 57, Figs. 2 and 4, actuated by a worm 50 adapted to be connected to the shaft 22 by a clutch 51. The clutch 51 is moved by an arm 52 of a three-armed lever loosely mounted on a shaft 53. Another arm 54 of the lever is provided with a roller adapted to enter either of two diametrically opposite notches 66 in a cam 65 secured to the shaft 64, and the third arm 55 engages a cam 60 carried by a shaft 59 actuated by a worm-wheel 58 and worm 56 adapted to be connected to the Shaft 22 by a clutch 67. The worm 50 is of quicker pitch than the worm 56, so that the wheed 57 rotates faster than the wheel 58. The cam 60 is formed with two projections 61, 62, and, in the inoperative position of the machine when the back 77 is retracted, the end of the arm 55 lies between the two projections. When the shaft 59 commences to rotate, the projection 61 actuates the arm 55 to connect the clutch 51 so that the back is moved during a, half revolution of the shaft 64 to close the mould. At the end of half a revolution of the shaft 64, the cam is in such a position that the roller on the arm 54 can be forced by the spring 63 into one of the notches 66, thus disconnecting the clutch 51 and stopping further movement of the shaft 64 and back 77. The end of the arm 55 runs on the circular part of the cam 60 during the time that the metal is being poured into the mould and is cooling. The projection 62 then acts on the arm 55 to cause the re-engagement of the clutch 51, and the consequent retraction of the back and rotation of the core. Driving-mechanism. The clutch 67 is actuated by one arm 68 of a three-armed lever secured on the shaft 53; another arm 69 of the lever carries a roller running on the surface of a cam 70 and adapted to engage under the influence of a spring with a notch therein when the machine is to be stopped; and the third arm 71 comprises the starting-handle of the machine. The arm 68 carries an extension 96, which is adapted to be engaged, when the machine is. first started, by a part 95 of a spring-actuated pawl 94 loosely carried by the shaft 59, When the extension 96 is engaged by the pawl 94, the parts are locked in position for the repeated operation of the machine, the arm 71 of the lever being held in the position shown in Fig. 4 against the action of its spring. Metal-pouring mechanism. A cam 92. Fig. 6, driven from the shaft 59 is engaged by a spring- actuated pawl 101 mounted on the shaft 59. The cam is circular except for a notch 92<a>, and when the pawl 101 engages the notch, the other end of the pawl is adapted to engage an offset projection 103 on a lever 99 to prevent its movement under the influence of a cam 98 secured on the shaft. 59. Normally, the pawl 101 is in such a position, under the influence of the circular part of the cam, that the lever 99, which is pivoted on a stud 81, is moved by the cam 93 to actuate the metal-pouring device. The other end of the lever is connected by a cable 100 to a segment 106, Figs. 18, 23, and 26 secured on a shaft 108 and acted on by a weight 113. A cam 107 on the shaft 108 is adapted to engage an arm 110 on the trunnions 111 of the ladle 112 mounted above the melting-pot 128. When the cable 100 is released by the action of the cam 98 on the lever 99. the weight 113 turns the shaft 108 and causes the cam 107 to tilt the ladle and deliver the contained metal into the conduit 114 through which it passes to the mould. The trunnions 111 carry an arm 116 having a pin 118 movable in a slot 119 in a spring-held rod 120, but the rod can be moved and locked in position by the engagement of a notch with a portion of the machine, to prevent movement of the ladle. The ladle is supplied with metal from the melting-pot 128 by means of a pump 132 driven from a motor 138 mounted above the pot, the metal being delivered through a pipe 134. The ladle is provided with overflow openings 125, 126 through which excess metal returns to the pot through a passage 127, a continuous circulation being thereby maintained. The pump acts continuously, and when the ladle is tilted, the metal is discharged into the passage 127. The ladle is provided with an adjustable stop 115. Plate trimming and delivery arrangements. As the back is drawn away from the care after the plate has solidified. a cam 148, Fig. 2, on the shaft 64 acts on a lever 147 pivoted on the shaft 53 and connected by an adjustable link 146 to a pivoted bracket 143, Fig. 13. carrying a shaft 142 driven continuously from the shaft 24. Saws 144, 145 are mounted on the shaft 142 and serve to trim the plate as the core is rotated. As the back moves towards the core again, fingers 155, Fig. 2, on the back, engage the edges of the plate and strip it from the core. Counting-mechanism. The shaft 59 carries a gear-wheel 79, Fig. 5, in mesh with a gear-wheel 80 loosely mounted on a sleeve 82, which itself is loose on the stud 81. The sleeve 82 is integral with a guard 83 for the gear-wheel 80, and the guard is provided with a spring-pressed plunger 85 adapted to engage with any one of a number of concentric apertures 87. Figs. 4. 5, and 6, in gear-wheel 80. The arrangement is such that the gearwheel 80 rotates the distance between two apertures for each rotation of the shaft 59. A disc 90 is secured to the stud 81 and its surface is provided with marks corresponding in number to the apertures 87. The marks are numbered from 0 upwards. and a. " stop " mark is also provided. The plunger 85 is set opposite the figure corresponding to the number of plates to be cast and engages the corresponding aperture in the gear-wheel 80. The cam 92 is keyed to the sleeve 82 together with a cam 91, and the cams are thus set by the setting of the guard 83. The cam 91. Fig. 4, is circular but for one projection, which is adapted to engage the pawl 94 when the plunger 85 reaches the " stop " position on the disc 90, thus releasing the lever 68, 69, 71 and allowing it to be actuated by its spring to disconnect the clutch 67 and stop the machine. After the casting of the last plate, a further complete cycle of operations, except that of pouring the metal, is necessary in order to effect the trimming and delivery of the plate. and for this reason the extra " stop " division is provided on the gear-wheel 80. and the notch 92a in the cam 92 is sufficiently large to receive the pawl 101 during two rotations of the shaft 59.